[PATCH 07/14] ARM: v6k: select clear exclusive code seqences according to V6 variants
Russell King - ARM Linux
linux at arm.linux.org.uk
Mon Jan 17 14:23:22 EST 2011
If CONFIG_CPU_V6 is enabled, then the kernel must support ARMv6 CPUs
which don't have the V6K extensions implemented. Always use the
dummy store-exclusive method to ensure that the exclusive monitors are
cleared.
If CONFIG_CPU_V6 is not set, but CONFIG_CPU_32v6K is enabled, then we
have the K extensions available on all CPUs we're building support for,
so we can use the new clear-exclusive instruction.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
arch/arm/kernel/entry-header.S | 14 +++++++-------
arch/arm/mm/abort-ev6.S | 6 +++---
2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index ae94649..051166c 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -76,13 +76,13 @@
#ifndef CONFIG_THUMB2_KERNEL
.macro svc_exit, rpsr
msr spsr_cxsf, \rpsr
-#if defined(CONFIG_CPU_32v6K)
- clrex @ clear the exclusive monitor
- ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr
-#elif defined (CONFIG_CPU_V6)
+#if defined(CONFIG_CPU_V6)
ldr r0, [sp]
strex r1, r2, [sp] @ clear the exclusive monitor
ldmib sp, {r1 - pc}^ @ load r1 - pc, cpsr
+#elif defined(CONFIG_CPU_32v6K)
+ clrex @ clear the exclusive monitor
+ ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr
#else
ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr
#endif
@@ -92,10 +92,10 @@
ldr r1, [sp, #\offset + S_PSR] @ get calling cpsr
ldr lr, [sp, #\offset + S_PC]! @ get pc
msr spsr_cxsf, r1 @ save in spsr_svc
-#if defined(CONFIG_CPU_32v6K)
- clrex @ clear the exclusive monitor
-#elif defined (CONFIG_CPU_V6)
+#if defined(CONFIG_CPU_V6)
strex r1, r2, [sp] @ clear the exclusive monitor
+#elif defined(CONFIG_CPU_32v6K)
+ clrex @ clear the exclusive monitor
#endif
.if \fast
ldmdb sp, {r1 - lr}^ @ get calling r1 - lr
diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index f332df7..1478aa5 100644
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -20,11 +20,11 @@
*/
.align 5
ENTRY(v6_early_abort)
-#ifdef CONFIG_CPU_32v6K
- clrex
-#else
+#ifdef CONFIG_CPU_V6
sub r1, sp, #4 @ Get unused stack location
strex r0, r1, [r1] @ Clear the exclusive monitor
+#elif defined(CONFIG_CPU_32v6K)
+ clrex
#endif
mrc p15, 0, r1, c5, c0, 0 @ get FSR
mrc p15, 0, r0, c6, c0, 0 @ get FAR
--
1.6.2.5
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